1. Field of the Invention
The field of the present invention is helmets suitable for an occupant on a racing car, a motorcycle or the like, and more particularly, systems for controlling the opening and closing of a shield plate of a helmet including a cap body having a window opening in a front surface thereof, and a shield plate pivotally mounted on the cap body to open and close the window opening.
2. Description of the Prior Art
In general, a click stop mechanism is provided at a pivotally mounted portion of the shield plate on the helmet for stepwisely adjusting and maintaining the opening degree of the shield plate (for example, see Japanese Utility Model Publication Kokoku No. 4897/83).
In use of the helmet, it is a normal practice to maintain the shield plate at a small opening degree, thereby slightly permitting airstream to be introduced inside the shield plate, in order to prevent an inner surface of the shield plate from being clouded up with an exhaled breath of a user. In this case, in the prior art helmet, the maintaining of the shield plate at the small opening degree relies upon the click stop mechanism, but there is a limit for the maintaining force of such mechanism. Therefore, the shield plate may be opened to an extent more than necessary by a pressure of airstream, depending upon the orientation of the cap body with respect to the airstream.